import control    #pip install control
import matplotlib.pyplot as plt
import math
import numpy as np
K = 8
sys = control.tf(K,1) #系统
T, yout = control.step_response(sys)
plt.title("Simulation")  # 括号当中输入标题的名称
plt.plot(T,yout, label="Kp = %.1f" % K)
plt.legend(loc='best')  # 图列位置，可选best，center等
plt.show()
